The methods of preparation of retinol via several stages are described in U.S. Pat. Nos. 4,035,425, 4,064,183, 4,092,366. However, pure retinol prepared by the above methods is unstable in the light, easily photoisomerized and degraded with consequence that its activity is affected and generally stabilizer is added into the commercial product of retinol.
Even though the methods of preparation of retinol derivatives bonded various carbohydrates are disclosed in U.S. Pat. Nos. 4,473,503 and 5,631,244 in order to overcome the stability problem cited above, the steps of the preparation are complex, non-economical and are not satisfactory in terms of the stability.
Accordingly, it is required the needs of retinol derivatives which are stable in the light and aqueous solution and of which the preparation method is simple and economical.
The present invention solves the above problems and the object of the present invention is to prepare novel retinol derivatives, the preparation method having high yields, and the uses thereof.